Ball-seat apparatus and method

Abstract

An apparatus for restricting fluid flow includes: a ball receiving element disposed in a fluid conduit and configured to receive a ball that has been advanced through the fluid conduit and at least partially restrict fluid flow; and at least one feature disposed on at least one of the fluid conduit and the ball seat configured to reflect pressure waves generated by an impact between the ball and the ball seat.

1 . An apparatus for restricting fluid flow, comprising:
 a ball receiving element disposed in a fluid conduit and configured to receive a ball that has been advanced through the fluid conduit and at least partially restrict fluid flow; and   at least one feature disposed on at least one of the fluid conduit and the ball seat configured to reflect pressure waves generated by an impact between the ball and the ball seat.   
     
     
         2 . The apparatus of  claim 1 , wherein the at least one feature is a reflecting feature disposed at an inner surface of the fluid conduit. 
     
     
         3 . The apparatus of  claim 1 , wherein the at least one feature includes one or more discontinuities of an inner surface of the conduit. 
     
     
         4 . The apparatus of  claim 3 , wherein the discontinuities are a roughened portion of the inner surface. 
     
     
         5 . The apparatus of  claim 1 , wherein the at least one feature includes one or more moveable members configured to be actuated in response to the release or the impact. 
     
     
         6 . The apparatus of  claim 5 , wherein the one or more moveable members include one or more baffles. 
     
     
         7 . The apparatus of  claim 1 , wherein the at least one reflecting feature includes at least one saw tooth shape on an inner surface of the fluid conduit. 
     
     
         8 . The apparatus of  claim 1 , wherein the at least one feature includes a plurality of features distributed along a length of the fluid conduit. 
     
     
         9 . The apparatus of  claim 1 , further comprising a carrier including the fluid conduit and configured to be disposed in a borehole. 
     
     
         10 . The apparatus of  claim 9 , wherein the ball is configured to be at least one of dropped into and pumped through the fluid conduit. 
     
     
         11 . A method of restricting fluid flow, comprising:
 releasing a ball into a fluid conduit and receiving the ball in a ball receiving element disposed at the fluid conduit and at least partially restricting fluid flow; and   partially reflecting one or more pressure waves resulting from an impact between the ball and the ball receiving element by at least one feature disposed on at least one of the longitudinal conduit and the ball receiving element.   
     
     
         12 . The method of  claim 11 , wherein the at least one feature includes a moveable feature configured to be actuated to move at least one reflective surface into the fluid conduit. 
     
     
         13 . The method of  claim 12 , wherein the moveable feature is configured to be actuated by at least one of releasing the ball and the impact. 
     
     
         14 . The method of  claim 11 , wherein the at least one feature is a reflecting feature disposed at an inner surface of the fluid conduit. 
     
     
         15 . The method of  claim 11 , wherein the at least one feature includes one or more discontinuities of an inner surface of the conduit. 
     
     
         16 . The method of  claim 15 , wherein the discontinuities are a roughened portion of the inner surface. 
     
     
         17 . The method of  claim 11 , wherein the at least one reflecting feature includes at least one saw tooth shape on an inner surface of the fluid conduit. 
     
     
         18 . The method of  claim 11 , wherein the at least one feature includes a plurality of features distributed along a length of the fluid conduit. 
     
     
         19 . The method of  claim 11 , wherein reflecting includes generating multiple reflected pressure waves spread over time and destructively interfering with the at least one pressure wave. 
     
     
         20 . The method of  claim 11 , wherein partially reflecting includes generating at least one reflected wave that destructively interferes with the one or more pressure waves.